Method of treating metal surfaces to inhibit corrosion



Patented Mar. 7, 1939 i UNITED STATES PATENT OFFICE 2,149.25: I Marnon or rmrme mun suaracns To INHIBIT CORROSION Harry A. Cooper, Maplew ood, M].

No Drawing. Applieation'May 19, 1937, Serial No. 143,531

1 Claim. (01.29-0.)

This invention relates to metal coating proc- The process consists of bringing pellets such as esses and more particularly to a method of coatshot, punchings, filings or the like, made of ing articles made of corrodible metals such as iron stainless steel or other corrosion-resisting metals or steel with a thin coating of stainless steel or or alloys of metals into forcible contact with the 5 other corrosion-resisting metals or alloys of object which is being cleaned and coated. Thisis 5 metals. accomplished in the conventional manner either- An object of this invention is to provide during by forcing the pellets against the object by com-v the process of cleaning and polishing a method of pressed air or mechanical means or by tumbling rendering corrosion-resistant objects made of the object in the presence of the pellets.

in corrodible metals such as iron and steel. In all cases of corrodible metals or alloys the w A further object is to provide a method of coating pellets should be of a softer metal than cleaning and polishing objects made of stainless the object being coated, so that'as the softer pelsteel or other corrosion-resisting metals or allets forcibly hit the object, a minute quantity of loys of metals to give them a lasting and durable the stainless steel or corrosion-resisting metals finish and a non-corrodible surface. or alloys of metals is deposited on the surface The outstanding disadvantage in the use of of the object. As the process is continued the obiron and steel for manufacturing purposes is the ject will become covered with a thin, closely adrapid corrosion of the surfaces exposed to oxidahering pellicle or coating of stainless steel or the tion. There are many expedlents employed to corrosion-resisting metals or alloys of metals. In

90 overcome this disadvantage i. e. galvanizing, the case of objects made of stainless steel or cadmium plating, nickel plating, painting, etc. corrosion-resisting metals or alloys of metals, These expedients necessitate'extra steps and spepellets of a similar metal or alloy should be used. cial processesand equipment after the article is The use of pellets made-of stainless steel or otherwise complete and add materially to the other corrosion-resisting metals or alloys of time'and cost of manufacture. I have discovmetals in the cleaning and polishing of objects ered a method of rendering objects made of cormade of corrodible metals such as iron or steel, rodible metals such as iron-and steel corrosionresults in the deposit of a corrosion-resisting resistant during the process of cleaning and polcoating on the surface of the object. It has been ishing without adding to the cost of the finished found that when corrosion-resisting pellets are 30 article. substituted for the ordinary steel pellets in the Heretofore the use of steel balls-or shot in process of cleaning and polishing objects made cleaning and polishing objects made of stainless of stainless steel or other corrosion-resisting steel and other alloys has resulted in-a tendency metals or alloys ofmetals, there results a prodfor the object to corrode easily. I have discovnot with much higher corrosion-resisting ered that in the processof cleaning and polishqualities.

- ing, the steel balls or shot deposit a thin coat- What I claim is: ing of ordinary steel on the object, thus destroy- The method of cleaning andpolishing staining the most valuable property of the stainless less steel objects which consists in forcibly consteel or alloy. 'By using the method hereinafter tacting the surface of the object with stainless 40 described this tendency towardcorrosion disapsteel pellets. 4

Mars and the object retains all the desirable HARRY A. COOPER. 0 properties inherent in stainless steel or the. particliiar metal or-alioy tiled.- 

